In order to constantly monitor the condition of the machine, in particular the condition of the antifriction bearings in machines, measuring systems (vibration monitors) are arranged in a stationary manner on machines. For this purpose, these vibration monitors are screwed into the lubrication hole of antifriction bearing housings in order to register the machine vibrations in the immediate vicinity of the antifriction bearing. In order to permit relubrication of the antifriction bearings without dismantling the vibration monitor, the vibration monitor has a hollow mounting pin.
Such a measuring system is described, for example, in U.S. Pat. No. 6,236,328 B1. The problem with the vibration monitor shown there is that the printed circuit boards are connected directly to the mounting pin, and the vibration sensor is arranged on one of the printed circuit boards. As a result of the direct arrangement of the printed circuit boards on the mounting pin, all the vibrations of the machine system are transmitted to the bearing pin and therefore to the printed circuit boards. As a result of the direct fixing of the printed circuit boards to the mounting pin, the electronic components are highly loaded by the continuous vibrations (possible early failure of the components). The direct fixing of the printed circuit boards to the mounting pin firstly dampens the machine vibrations and, secondly, the printed circuit boards have an inherent vibration behavior, so that the vibration sensor on the printed circuit boards is able to pick up only damped or distorted vibrations. As a result of this damped or distorted sensing of the vibrations, the interpretation of the measured signal is extremely difficult and changes in the vibratory behavior of the machine can be registered only coarsely.
There is, therefore, the object of proposing a measuring system in which the vibration sensor can pick up the machine vibrations in undamped form and the printed circuit boards having the electronic components are largely protected with respect to the machine vibrations.